1. Field of the Invention
The present invention relates to light emitting diode (LED) technology and, more particularly, to a lens cover for an LED. The present invention finds particular application as a reinforced lens cover and a method of manufacturing said reinforced lens cover and will be described with particular reference thereto. However, it is to be appreciated that the present invention may relate to other similar environments and applications.
2. Discussion of the Art
An LED assembly generally includes a base, an LED supported by the base and a cover over the LED. The LED is typically a piece of semiconductor material having wire leads extending therefrom for delivering current to the LED. The cover is typically a substantially transparent material having a dome shape and acting as a lens for light emitted from the LED. When assembled, the cover and the base serve to encapsulate the LED and protect it from adverse environmental effects. The optically transmissive cover additionally serves to enhance light emission from the LED and control external radiation patterns from the LED.
Several design aspects are involved in providing a suitable cover for an LED. The cover should be sufficiently rigid to provide a structurally sound member. Moreover, the cover should be at least partially substantially transparent and minimize the amount of light attenuation so as to not adversely affect the spectrum of light which is emitted by the LED, particularly as the cover ages. Heretofore, these design aspects often competed with one another, i.e., an improvement in one of the aspects often corresponded to a weakening in another of the aspects.
LED covers that attempted to balance the design aspects were often difficult to manufacture. For example, one type of conventional cover is formed in two parts. The two-part cover typically includes a hard outer shell and a soft resilient inner shell, often formed of silicone, defining a space therein for the LED substrate. The hard outer shell of the two part cover enables it to be structurally sound while the soft inner shell reduces the likelihood that the LED substrate will be damaged. One drawback of the two-part cover is that the hard outer shell often has low heat characteristics. Thus, there is a need for an LED cover that balances the design aspects discussed above while being relatively easy to manufacture.